Process for the manufacturing of carbon paper for use on typewriters



i Patented Nov. 23, 1926. v

UNITED STATES PATENT OFFICE.

HENRY N. DONS, OF ROCHESTER, NEW YORK.

PROCESS FOR THE MANUFACTURING OF CARBON PAPER- FOR USE ON TYPEWRITERS.

No Drawing. Application filed December 4, 1925. Serial No. 73,267.

My invention relates to the manufacturing without sorting or bleaching Which would of carbon paper used for typewriting and not alone make the paper much cheaper but other purposes. It has been customary to also stronger as it is a well known fact that cover the one side of the carbon paper only. the bleaching with chemicals decreases mate- 45 My invention covers both sides of the paper, rially the strength of the fiber. The black one side with coloring matters, oils, fatty aniline make it possible to use the paper acids, waxes, etc, as is usual; and the other stock in its natural color without sorting, as side with rosin and black aniline dissolved the black aniline is able at all times to protogether in a liquid which evaporates quickly duce a uniform satisfactory black color more P such as chloroform, ether, benzine and such or less deep according to the amount of aniliquids, and does not reduce the strength of line used, whereas the other aniline colors, the paper at the time it is not dry, and passby mixing with the different colors of the ing through the coating machine which any paper stock, will produce secondary colors, matters dissolved in water will do. This sonot satisfactory because .on account of the 5d lution leaves a black sheet'which does not different amounts of colored rags used to give off any color under pressure or in han produce the paper stock it is impossible to dling, nor does it absorb color from other produce from them a product which at all sheets when dry, and does not leave the side times has the same color, unless it is bleached. of the paper covered with rozin, black ani- It is therefore impossible to state the exact 60 line and liquid in a state which would be adamount of aniline to use in the solution, but hesive, which makes it entirely different from the amount of rosin is generally from 8 to a patent formerly issued which patent ex- 12% compared to the solvent. Shellac either pressly stipulates that one side was left in an synthetic or natural is preferred but use of adhesive state. other rosins not excluded. It is also possible 65 According to my process it will be necesto use the paper stock mixed with a larger sary to carry only one color of paper stock, amount of wood pulp because the unbleached whereas now it is necessary to carry several fiber is so much stronger than the bleached different colors. Thereby we create an opwhich is now used. portunity for a big saving by carrying less hat I claim to be new and useful and for stock and the elimination of a large amount which I ask Letters Patent is:

of waste. It also eliminates special packing The process of making carbon transferfor ocean shipments as the paper is fully paper which consists in coating one side with protected from dampness. This therefore the usual mixture of wax, fatty acid, oils and eliminates another big item of expense by coloring material, and the other side with a 75 using rosin and black aniline in solution as strengthening composition consisting of anistated above, the fibers of which the paper line-black and rosin dissolved in a volatile consists are gummed together by the rosin solvent-which, because of its quick evaporawhen it is dry, which makes it also watertion, will have no deleterious influence on-the proof and a great deal stronger. The addipaper itself. tion of black aniline makes it possible to use paper made of paper stock of mixed colors HENRY N...DONS. 

